in cxx/fbjni/detail/Exceptions.cpp [222:232]
void denest(const std::function<void(std::exception_ptr)>& func, std::exception_ptr ptr) {
FBJNI_ASSERT(ptr);
try {
std::rethrow_exception(ptr);
} catch (const std::nested_exception& e) {
denest(func, e.nested_ptr());
} catch (...) {
// ignored.
}
func(ptr);
}